Is there a relationship between three-dimensionally measured Baker's Cyst volume and knee pathologies?

Objective: Baker’s cyst (BC) is also known as popliteal cyst. To evaluate its effect on intra-articular pathology, it is important to have the exact volume of the cyst. As BC may change its shape due to mass effect of the surrounding anatomic structures, it is difficult to measure the exact volume of BC. This study examined the relationship between three-dimensionally measured BC volume and symptomatic intra-articular knee pathologies. Materials and Methods: The magnetic resonance (MR) images of 45 patients with symptomatic knees were retrospectively examined. The BC volumes were measured via volumetric analysis. The joint effusion was examined in the sagittal plane in T2-proton density-weighted images. The medial plicae were assessed in accordance with the modified Sakakibara classification. Using the MR images, the meniscuses were classified in accordance with the meniscus rupture classification of Stoller et al. The cartilaginous lesions were analyzed using an MR grading system. In this study, correlations between the following measures were analyzed: BC volume and effusion level, medial plica presence, medial femoral condyle, medial tibial condyle, lateral femoral condyle and lateral tibial condyle cartilage degeneration, and medial meniscus anterior horn, medial meniscus posterior horn, lateral meniscus anterior and posterior horn ruptures. Results: Cartilage degeneration, medial plicae, increase in intra-articular effusion, and increase in the BC volume were found to be statistically significant (p<0.01). Conclusion: Cartilage degeneration, medial plicae, and increase in intra-articular effusion may increase the BC volume. We believe that this study may contribute to clinicians in understanding the relationship between BC volume changes and pathologies causing intra-articular knee symptoms

Grinding mechanism of sepiolite for high viscosity industrial applications

Bu &ccedil;alışmada yaş ve kuru olarak uygulanan farklı &ouml;ğ&uuml;tme tekniklerinin sepiyolit liflerini serbestleştirmedeki etkinliği boyut kontrolu ile birlikte araştırılmıştır. Katı konsantrasyonu, karıştırmanın şiddeti-s&uuml;resi ve &ouml;ğ&uuml;tme şeklinin sepiyolitin reolojik &ouml;zellikleri &uuml;zerinde onemli etkisinin olduğu g&ouml;r&uuml;lm&uuml;şt&uuml;r. Kuru &ouml;ğ&uuml;tme işlemlerinin &ouml;ğ&uuml;tme s&uuml;resindeki artışla beraber sepiyolitin yapısına zarar verdiği ve 2 saatlik &ouml;ğ&uuml;tme s&uuml;resinden sonra tekrar floklaşmadan dolayı tane boyutunun irileştiği ve lifsi yapısının kaybolduğu, yerini şekilsiz k&uuml;relerin aldığı g&ouml;r&uuml;lm&uuml;şt&uuml;r. Yaş &ouml;ğ&uuml;tmede ise sepiyolitin lifsi yapısının korunduğu tespit edilmiştir. Elde edilen verilerin değerlendirilmesinde zeta potansiyel, y&uuml;zey alanı ve SEM (taramalı elektro mikroskop) g&ouml;r&uuml;nt&uuml;lerinden faydalanılmıştır. &nbsp;Anahtar Kelimeler: Sepiyolit, &ouml;ğ&uuml;tme, viskozite.Clay minerals have a wide range of industrial applications including thickeners and flow regulators which are known as rheological additives. For this purpose, bentonite type layered smectite group clays and needle structured sepiolite and attapulgite type clays are used. The mechanisms of gelling for both clays are different due to their unique structures. The rheological properties of these suspensions depend on such parameters as concentration, the intensity of agitation and pH. These properties make sepiolite suspensions very useful thixotropic materials and thickeners. In this study, the effect of mode of grinding, dry and wet on disintegration of sepiolite fibers was investigated under controlled particle size. Physical parameters are shown to impart a pronounced effect on the viscosity of sepiolite; the viscosity increases with increasing the energy of agitation, but increase in viscosity against solids concentration is not linear but polynomial. The results were interpreted with zeta potential, surface area measurements and SEM photographs. It is shown that the mode of grinding has a significant effect on the rheological properties of sepiolite. Dry grinding process adversely affects the structure of sepiolite and after 2 hours of grinding, the grain size is enlarged due to agglomeration of fibers into spheres. In wet grinding, the fiber structure of sepiolite was preserved along with a plausible size reduction. These results were also corroborated with zeta potential results.  Keywords: Sepiolite, grinding, viscosity

The mechanism of NaCl action on the selective separation of Na-feldspars and K-feldspars

G&uuml;n&uuml;m&uuml;zde y&uuml;ksek i&ccedil;erikli Na-feldspat veya K-feldspat i&ccedil;eren cevherler t&uuml;kenmiştir. Bu &uuml;r&uuml;nleri barındıran cevher yataklarından her ikisinin de se&ccedil;imli olarak end&uuml;strinin istediği standartlarda kazanılması gerekmektedir. Benzer fizikokimyasal &ouml;zelliklere sahip olmaları, bu minerallerin se&ccedil;imli olarak birbirinden ayrılabilmeleri i&ccedil;in tek zenginleştirme y&ouml;nteminin flotasyon olduğunu g&ouml;stermektedir. Bu ama&ccedil;la Na ve K iyon selektif elektrodları ile albit ve mikroklinden &ccedil;&ouml;zeltiye ge&ccedil;en ve &ccedil;&ouml;zeltiden mineral &uuml;zerine adsorplanan Na+ ve K+ iyon miktarları &ouml;l&ccedil;&uuml;lm&uuml;şt&uuml;r. &Ccedil;ıkarılan adsorpsiyon izotermleri &uuml;zerinde iyon değiştirme ve iyon adsorpsiyon b&ouml;lgeleri tesbit edilerek Na-feldspat ile K-feldspatın se&ccedil;imli olarak birbirinden ayrılmasının etki mekanizması olarak a&ccedil;ıklanmıştır.Anahtar Kelimeler: Feldspat, mikroklin, albit, flotasyon, adsorpsiyon, zenginleştirme.Albite (Na-Aluminum Silicate) and microcline (K-Aluminum Silicate) are the major commercial feldspar minerals. Over 90 % of the feldspar minerals are utilized in glass and ceramics industry. While K-feldspar is mainly used in ceramics industry, Na-feldspar is used in glass industry. Feldspars are also used in plastics, paint and welding electrodes. The ratio of K/Na and the presence of colored impurities such as Fe, Ti dictate the quality of feldspar. High grade Na-feldspar and K-feldspar are currently found in limited quantities. Therefore, these products meeting the quality standards of industry must be supplied from the mixed ore deposits of both minerals. Because of similar physicochemical properties, the only enrichment method to selectively separate Na and K feldspars is flotation. In our past studies, microflotation was studied in the presence of mono and multivalent salts in order to understand the mechanism of selective separation between Na and K feldspars. In this context, Na and K ions selective electrodes are used to determine the concentrations of Na and K ions released in to the solution from albite and microcline and those adsorbed ions onto the minerals surfaces. Adsorption isotherms were constructed and regions identifying ion adsorption and ion exchange are delineated with the aim of determining the mechanism of selective separation of Na and K feldspars from each other.Keywords: Feldspars, microcline, albite, flotation, adsorption, beneficiation

Preparation of nano-fiber structured sepiolite determining fiber size with atomic force microscopy (AFM)

Sepiyolit, mikrofiber yapılı ve y&uuml;ksek y&uuml;zey alanına sahip doğal bir kil mineralidir. Y&uuml;ksek y&uuml;zey alanı, lifsi yapısı, porozitesi, kristal morfolojisi ve kompozisyonu, y&uuml;zey aktivitesi, d&uuml;ş&uuml;k konsantrasyonlarda y&uuml;ksek viskoziteli duraylı s&uuml;spansiyonlar oluşturma gibi sıra dışı &ouml;zellikleri mevcuttur. Sepiyolitin yapısı, ısıl işlemlere, asitle muameleye ve ayrıca uygulanabilecek mekaniksel işlemlere karşı hassasiyeti sayesinde mineralin sahip olduğu sorptif, katalitik ve reolojik &ouml;zellik gibi en faydalı &ouml;zelliklerini değiştirmek m&uuml;mk&uuml;n olabilir. Sepiyoliti oluşturan lif demetleri suda bir mekanik karıştırıcı kullanılarak dağıtılırsa, bir ağ yapı i&ccedil;erisinde par&ccedil;acık i&ccedil; ve dış y&uuml;zeyleri artan lifler daha fazla su adsorplama ve par&ccedil;acıklar arasında daha fazla su tutulmasını sağlayarak viskozitenin artırılmasına yardımcı olmaktadır. Bu &ccedil;alışmada yapılan viskozite &ouml;l&ccedil;&uuml;mlerine g&ouml;re; 21000 rpm hızda y&uuml;ksek hızlı bir mekanik karıştırıcıda 3 dakika boyunca işleme tabi tutularak hazırlanan p&uuml;lp ile 5 rpm spindle hızında &ouml;l&ccedil;&uuml;len en y&uuml;ksek g&ouml;r&uuml;n&uuml;r viskozite olarak 9600 cP elde edilmiştir. Karıştırma hızının d&uuml;şmesi ile viskozite değerleri d&uuml;şmektedir. Artan s&uuml;reler ise kritik bir eşiğe kadar viskozite değerini artırdıktan sonra d&uuml;ş&uuml;rmektedir. Nano boyutlara kadar serbestleşmesi beklenen sepiyolitin, birim liflere ayrılmasını teyit etmek ve bu &ouml;l&ccedil;ekte boyutlarının belirlenebilmesi nano &ouml;l&ccedil;ekli malzeme hazırlanabilmesi i&ccedil;in &ouml;nemli bir aşamadır. Bu nedenle daha &ouml;nce smektit tipi killerle ger&ccedil;ekleştirilen Atomik Kuvvet Mikroskobu (AFM) &ccedil;alışmalarına paralel olarak inceleme ger&ccedil;ekleştirilmiştir. Sepiyolit i&ccedil;in AFM inceleme numunesi hazırlama y&ouml;ntemi belirlenmiş ve ortalama olarak en iyi viskoziteyi veren p&uuml;lpteki lif boyutları 249*29*1127 nm (genişlik*y&uuml;kseklik*uzunluk) olarak tespit edilmiştir. Alınan g&ouml;r&uuml;nt&uuml;lerde 3 dakika mekanik dağıtma &ouml;ncesinde liflerin demetler halinde olduğu, sonrasında sepiyolit liflerinin kırılarak par&ccedil;alanmakta olduğu g&ouml;r&uuml;lm&uuml;şt&uuml;r. Bu kırık lifler, boyutlarının k&uuml;&ccedil;&uuml;kl&uuml;ğ&uuml; nedeniyle rastgele bir ağ yapı i&ccedil;erisinde kendilerine yer bulamayarak viskoziteyi d&uuml;ş&uuml;rmeye neden olmaktadır. &nbsp;Anahtar Kelimeler: Sepiyolit, mekanik dağıtma, AFM ile boyut tayini.Sepiolite is a natural hydrated magnesium silicate clay mineral with microfiber structure and high surface area. Fibers are constructed by tetrahedral and octahedral structured oxides within half cell formula of Si12O30Mg8(OH,F)48H2O. Sepiolite has special futures like; high surface area, fiber structure, porosity, tunnel/channel composition, crystal morphology, surface activity and formation of stable high viscosity suspensions at low solid concentrations. This unique structure of sepiolite can be altered by heat and/or acid activations. It also exhibits severe sensitivity to any mechanical perturbations; any interference may result as structural changes which can enhance or deteriorate the characteristics of sepiolite. Cation exchange capacity, fiber dimensions (fiber length/fiber width) and the type and amount of accompanying impurities are the main factors identifying the reologic behavior of sepiolite pulps. If sepiolite fiber bundles are disintegrated in water with a mechanic impeller, these particles may form random structures in the form of networks and increase the apparent viscosity values. Better dispersion of these fibers leads to an enhancement of water sorption on the fiber surface and in turn in inner galleries, resulting in entrainment of water within the network and thus viscosity increase. In this study, the dimensions of sepiolite fibers after mechanical dispersion are investigated based on a technique described in the literature for monitoring the sizes of montmorillonite and smectite type clays by Atomic Force Microscope (AFM). Unlikely the previous studies where a sepiolite fiber sizes were measured with SEM technique; conducting AFM study to determine the difference in the sizes of sepiolite fibers is unique. The mechanical dispersion process is conducted as a function of time and stirring rate, and the results of rheological behavior is followed through viscosity. A Turkish sepiolite sample of 65 10% purity was obtained from Eskişehir region. Sepiolite suspensions were prepared at 3%solids by weight in pure water as described in the literature. As sepiolite suspensions are characterized by time dependent flow behavior, they exhibit thixotrophy. The viscosity measurements were taken at different spindle rates but particularly at 5 rpm spindle rate. The highest viscosity value was obtained with the suspensions prepared at the highest stirring rate of 21.000 rpm. The samples run at 1, 3, 5 min. and the corresponding viscosity values of 6400, 9600, 4800 cP respectively were collected for AFM investigations. Several techniques have been established to investigate platelet structured clays. For our special case, these procedures were overrun and modified to investigate the fiber structured sepiolite samples; this involves dropping of 1 ml dilute sepiolite suspension onto a clean mica surface. The drop is dried with nitrogen gas and the mica plate is stored in a Petri dish till AFM investigation to avoid any airborne impurities to settle on the surface. For AFM investigations, Nanoscope III model AFM set up was used at the tapping mode to produce 512*512 pixel graphics of sepiolite settled on the mica surface. The sample prepared for 1 minute stirring, represents bundles consisting of approximately 50-60 fibers. Ensuing sample of 3 minutes stirring was made with fiber groups of 5-10. Increase in apparent viscosity values upon increasing stirring time, indicates the presence of loosened bundles and thus better network. However, when the stirring period is increased to 5 minutes the viscosity value decreases and the AFM graphics, showed the failure in size uniformity with accompanying a weak networking. AFM graphics n-Surf 1.0 Beta visualizer program coupled with XYit program is used for numerical analysis of the fiber or bundle dimensions. Finally the collected data are averaged with Excel program. Investigating a total of 130 profiles, the average height*width of 1, 3 and 5 minute stirring is found as 514*50, 249*28 and 157*22 nm, respectively; the corresponding fiber or bundle lengths are 1643, 1126 and 1055 nm, respectively. As a result considering the average sizes, at the same percent solids, the number of fibers or groups in a suspension prepared at 3 minute stirring is 8 times more than that of 1 minute stirring, indicating a better network leading to higher viscosity. As opposed to this,&nbsp; further stirring at 5 minute stirring deteriorated the dimensions of fibers and the formation of network due to fracture of fibers.&nbsp;Keywords: Sepiolite, mechanic dispersion, size determination with AFM

Evaluation of the powering extrapolation of a ship with a gate rudder system, including ageing and fouling effects

This paper is based on the evaluation results of the calm water powering extrapolation of a 90-meter general cargo vessel, originally built with a conventional rudder system (CRS) and later retrofitted with an innovative energy-saving device (ESD) known as the Gate Rudder System® (GRS), as part of the EU H2020 Project GATERS. The power estimation of the vessel was conducted using an adapted extrapolation procedure based on the scaled model tests of the vessel in a towing tank, validated by the three sets of sea trials. The first sea trial was performed when the ship was new, while the latter two were conducted during the project timeline, before and after the GRS retrofit. This paper aims to adapt the ITTC-78 power extrapolation method to predict the power performance of a ship retrofitted with the GRS for the first time in the maritime industry. Within this framework, the specific objectives of the paper are to describe and validate the proposed method using relevant power-speed data of the GATERS project target vessel (M/V ERGE) initially equipped with the CRS and later replaced by the retrofit GRS to achieve the project objective. Due to the real-world circumstances of retrofitting a 13-year-old ship with a novel energy-saving device, investigating the effects of ageing, hull roughness, and fouling has also become one of the key objectives of the paper. The findings demonstrate the ageing effect on the target ship’s powering performance after retrofitting with GRS, highlighting the need for special consideration of power extrapolation alongside the hull fouling effects. The paper also demonstrates that the GRS is an emerging ESD, as a retrofit beside newly built ships with GRS, which improved the powering performance of the project target vessel, achieving a remarkable 25% power saving based on the comparative full-scale sea trials

Poly(ethylene terephthalate)-clay nanocomposite multifilament yarn: Physical and thermal properties

Poly(ethylene terephthalate)/clay nanocomposite multifilament yarn was manufactured by conventional masterbatch approach. Poly(butylene terephthalate) was used as a carrier polymer in masterbatch steps. The masterbatches were diluted into pilot melt spinning machine and subsequently drawn with 2.65 ratios to prepare fully oriented yarn. The degree of dispersion in nanocomposite fibers was analyzed by X-ray diffractometry and scanning electron microscopy. Even though the addition of nanoclay reduced mechanical properties of nanocomposite fibers, dimensional stability could be improved at certain clay contents. The flammability properties were sufficiently improved, and no significant changes were observed with increasing clay content. The main novelty of this paper is the development of a proper approach for the selection of optimum carrier polymer for nanoclay in masterbatch preparation, as well as proper nanoclay for desired polymers. The acid-base approach is used in evaluating the surface free energy of commercial nanoclay and calculation the total interaction energies between polymer and clay surfaces. Such an approach gives adequate information about polymer-clay compatibility and provides a useful tool in the selection of optimum carrier polymer, as well as proper nanoclay for the desired polymer during masterbatch preparations.Ministry of Science, Industry & Technology - TurkeyKorteks Mensucat Tic. San. A.S. (Bursa, Turkiye) through the SanTez Projects (Industrial Ph.D. Projects) (00492.STZ.2009-2

Revisiting flotation mechanisms of the selective separation of alkali feldspars in the presence of NaCl

Selective separation of Na-feldspar (NaAl3SiO8) from K-feldspar (KAl3SiO8) by flotation appears to be the only alternative in commonly found mixed-type ore formations. For this purpose, various mechanisms in various studies have been proposed by which selective separation can be achieved in the presence of salt ions. These mechanisms under different flotation conditions are systematically discussed in this study. Literature review reveals that two adsorption mechanisms are operating in the presence of Na+ ions and natural pH: Ion exchange and ion adsorption. In mixed feldspar systems, the mineral surface properties change due to ion exchange of counter ions on K-feldspar surface and become suitable for amine adsorption, while Na-feldspar surface is suppressed due to co-ion adsorption leading to limited amine adsorption. Similar mechanisms occur in acidic conditions with fluorine ions which increases the dispersion of particles and provides selectivity for K-feldspar by forming AlSiF-amine complexes. K-feldspar at alkaline pH with NaOH is activated with fluorine ions at the previous flotation stages and then floated with amine releasing K ions into the solution. The ion exchange/ion adsorption mechanism seems effective in alkaline as well as in natural and acidic conditions

Tunçbilek Kömür Hazırlama Tesisi, kil içerikli atıkların özelliklerinin incelenmesi

Kömür hazırlama tesisi atık sularının flokülasyon yöntemiyle susuzlaştırılmasında kullanılacak reaktiflerin cinsi ve miktarının yanısıra atığın içerdiği mineral maddelerin özelliklerinin bilinmesi, çöktürme işleminin etkili ve ekonomik olması açısından önem arz etmektedir. Bu çalışmada, Tunçbilek Kömür Hazırlama Tesisi atık suyunda bulunan organik ve inorganik kökenli safsızlıkların karakterizasyonu, jeolojik bulgular desteğinde çeşitli analiz teknikleri kullanılarak yapılmıştır. Bunun için mikroskop incelemeleri, mineralojik analizler, termal (DTA-TGA) analizler, kimyasal analizler, karbon-kükürt ve kül analizleri ve tane boyutu analiz teknikleri kullanılmıştır. XRD bulguları tesis atığının başlıca kuvars, kaolenit, illit, muskovit ve kaolenit-montmorillonit mineralleri içerdiğini göstermiştir. Tamamı 0,180 mm altında yer alan tesis atığının % 28’i kil, % 62’si silt ve %10’u ise kum boyutundadır. XRD verileri desteğinde kimyasal analiz sonuçlarına göre, orijinal atık teorik olarak %25 civarında kil mineralleri (illit, kaolinit), %22 civarında muskovit ve %23 oranında kuvars ihtiva etmektedir. Kömür oranı ise %20 dolaylarındadır.In this working, in Tunçbilek coal processing plant which is organic extraction purityless of characterization was done with supporting geological discovery withusing instrumentals analysis techniques. Investigate of microscopes analysises of mineralogical, analysises of thermal (DTA-TG), chemical analysises, carbon- sulphur and ash analysises and analysises of the particle size were done to aimed at determination of properties of waste. In waste, the minerals, which are defining with X-rays analysises are quartz, kaolenite, illite, muscovite and kaolenite-montmorillonite. All of plant wastes particles take plant under 0.180 mm %28 of it is clay, %62 of it is silt, %10 of I is sand. Aimed at obtain data’s and XRD results, the original waste contains clay minerals around %25 (illite, kaolenite), muscovite around %22 and quartz around %23. However, the coal rate is %20

Tunçbilek Kömür Hazırlama Tesisi, kil içerikli atıkların özelliklerinin incelenmesi

Kömür hazırlama tesisi atık sularının flokülasyon yöntemiyle susuzlaştırılmasında kullanılacak reaktiflerin cinsi ve miktarının yanısıra atığın içerdiği mineral maddelerin özelliklerinin bilinmesi, çöktürme işleminin etkili ve ekonomik olması açısından önem arz etmektedir. Bu çalışmada, Tunçbilek Kömür Hazırlama Tesisi atık suyunda bulunan organik ve inorganik kökenli safsızlıkların karakterizasyonu, jeolojik bulgular desteğinde çeşitli analiz teknikleri kullanılarak yapılmıştır. Bunun için mikroskop incelemeleri, mineralojik analizler, termal (DTA-TGA) analizler, kimyasal analizler, karbon-kükürt ve kül analizleri ve tane boyutu analiz teknikleri kullanılmıştır. XRD bulguları tesis atığının başlıca kuvars, kaolenit, illit, muskovit ve kaolenit-montmorillonit mineralleri içerdiğini göstermiştir. Tamamı 0,180 mm altında yer alan tesis atığının % 28’i kil, % 62’si silt ve %10’u ise kum boyutundadır. XRD verileri desteğinde kimyasal analiz sonuçlarına göre, orijinal atık teorik olarak %25 civarında kil mineralleri (illit, kaolinit), %22 civarında muskovit ve %23 oranında kuvars ihtiva etmektedir. Kömür oranı ise %20 dolaylarındadır.In this working, in Tunçbilek coal processing plant which is organic extraction purityless of characterization was done with supporting geological discovery withusing instrumentals analysis techniques. Investigate of microscopes analysises of mineralogical, analysises of thermal (DTA-TG), chemical analysises, carbon- sulphur and ash analysises and analysises of the particle size were done to aimed at determination of properties of waste. In waste, the minerals, which are defining with X-rays analysises are quartz, kaolenite, illite, muscovite and kaolenite-montmorillonite. All of plant wastes particles take plant under 0.180 mm %28 of it is clay, %62 of it is silt, %10 of I is sand. Aimed at obtain data’s and XRD results, the original waste contains clay minerals around %25 (illite, kaolenite), muscovite around %22 and quartz around %23. However, the coal rate is %20